JP2004247198A

JP2004247198A - Battery pack

Info

Publication number: JP2004247198A
Application number: JP2003036464A
Authority: JP
Inventors: Hideyo Morita; 秀世森田; Hisashi Iwakuma; 久岩隈
Original assignee: Sanyo Electric Co Ltd
Current assignee: Sanyo Electric Co Ltd
Priority date: 2003-02-14
Filing date: 2003-02-14
Publication date: 2004-09-02
Anticipated expiration: 2023-02-14
Also published as: JP3806696B2

Abstract

<P>PROBLEM TO BE SOLVED: To couple a circuit board to thin batteries properly by attaching the two thin batteries connected in series and the circuit board in an ideal arrangement. <P>SOLUTION: In a battery pack, two thin batteries 1 are stacked so that a convex electrode end face 3 of one of the thin batteries 1 and a bottom end face 4 of the other of the thin batteries 1 are located on the same end face, and a circuit board 7 is placed so as to face a first end face 5 on which the convex electrode end face 3 and the bottom end face 4 are located. A short middle lead 8 is connected to a convex electrode 2 and the bottom end face 4 in the middle of the circuit board 7, so that the thin batteries 1 are connected in series. A pair of end leads 9 are connected to both ends of the circuit board 7, and the both ends of the circuit board 7 are connected to a positive electrode and a negative electrode of the respective thin batteries 1. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は、２個の薄型電池を内蔵するパック電池に関する。
【０００２】
【従来の技術】
ケースに薄型電池を内蔵するパック電池は、たとえば特許文献１の公報に記載される。このパック電池は、薄型電池の電極端面に回路基板を配置して、回路基板と薄型電池を一対のリードで連結している。この構造のパック電池は、ケースにひとつの薄型電池を収納しているので、２本のリードで薄型電池を回路基板に接続できる。このように、電極端面に回路基板を配置する構造で、ふたつの薄型電池を積層してケースに収納することができる。ふたつの電池は、並列あるいは直列に接続される。電池を並列に接続してケースに収納するパック電池は、薄型電池を同じ方向に向けて、すなわち薄型電池の凸部電極端面が同一面となるように積層し、積層している薄型電池の凸部電極と底側端面の電極をそれぞれリードで接続できる。電池を直列に接続するパック電池は、ふたつの薄型電池を同じ方向に向けて積層すると、直列に接続するリードが長くなる。この欠点は、ふたつの薄型電池を逆向きに向けて積層して解消できる。逆向きの薄型電池は、ひとつの薄型電池の凸部電極端面と他方の薄型電池の底側端面を同一面に位置させるので、短いリードで直列接続できる。さらに、電池を直列に接続するリードとは反対側の電極端面に回路基板を配置し、電池の凸部電極と底側端面の電極とをリードで接続して、短いリードで回路基板と電池を接続できる。したがって、直列に接続するこの構造のパック電池は、もっとも短いリードで電池を直列に接続し、さらに薄型電池を回路基板に接続できる。
【０００３】
【特許文献１】
特開２００２−８６０８号公報
【０００４】
【発明が解決しようとする課題】
しかしながら、以上の構造では、回路基板を薄型電池にしっかりと連結するのが難しく、また、各々の薄型電池の電圧を独立して検出するためには、薄型電池を直列に連結している反対側のリードを回路基板に接続する必要があり、電圧検出用のリードが長くなる欠点がある。本発明は、さらにこの欠点を解決することを目的に開発されたもので、本発明は、回路基板と薄型電池とを理想的な配置で連結して、回路基板をしっかりと薄型電池に連結でき、さらに直列に接続している薄型電池の正負の電極に接続している一対の端部リードの短絡を確実に阻止しながら回路基板に連結できるパック電池を提供することにある。
【０００５】
【課題を解決するための手段】
本発明のパック電池は、ふたつの薄型電池１を積層している。薄型電池１は、凸部電極端面３に凸部電極２を設けており、凸部電極端面３と反対側の電極端面である底側端面４を凸部電極２と異なる極性の電極としている。ふたつの薄型電池１は、一方の薄型電池１の凸部電極端面３と他方の薄型電池１の底側端面４とが同一端面に位置するように積層している。さらに、パック電池は、ひとつの薄型電池１の凸部電極端面３と他方の薄型電池１の底側端面４とが位置する第１の端面５に対向して回路基板７を配置している。回路基板７と対向する第１の端面５に位置する凸部電極端面３と底側端面４に中間リード８を接続し、この中間リード８でふたつの薄型電池１を互いに直列に電気接続し、さらにこの中間リード８を回路基板７の中間部分に接続している。また、回路基板７の両端部分には一対の端部リード９を接続して、中間リード８と端部リード９は回路基板７の片方の側縁で折曲している。一対の端部リード９は、一方をひとつの薄型電池１の凸部電極２に、他方を他方の薄型電池１の凸部電極２と反対側の電極に接続しており、中間リード８と端部リード９とでふたつの薄型電池１に回路基板７を連結している。
【０００６】
パック電池は、一対の端部リード９を、保護素子１０を介して薄型電池１の電極に接続することができる。
【０００７】
さらに、パック電池は、一対の端部リード９の端部を、第１の端面５の反対側にある第２の端面６に位置している薄型電池１の凸部電極２と底側端面４とに接続できる。さらに、パック電池は、薄型電池１の間に絶縁材１１を配設し、この絶縁材１１を、第２の端面６から突出させて、第２の端面６の凸部電極端面３と底側端面４とに接続している一対の端部リード９の間に配置して、絶縁材１１で端部リード９を確実に絶縁できる。
【０００８】
パック電池は、薄型電池１をケース１２に収納し、ケース１２の内面であって絶縁材１１と対向する位置に凹部１３を設けて、絶縁材１１でより確実に一対の端部リード９を絶縁できる。さらに、ケース１２の内面に設けている凹部１３の両側に、薄型電池１の凸部電極端面３と底側端面４に向かって突出する突出部１４を設け、この突出部１４と電極端面との間に端部リード９を配設して、さらに確実に一対の端部リード９を絶縁できる。
【０００９】
【発明の実施の形態】
以下、本発明の実施例を図面に基づいて説明する。ただし、以下に示す実施例は、本発明の技術思想を具体化するためのパック電池を例示するものであって、本発明はパック電池を以下のものに特定しない。
【００１０】
さらに、この明細書は、特許請求の範囲を理解しやすいように、実施例に示される部材に対応する番号を、「特許請求の範囲の欄」、および「課題を解決するための手段の欄」に示される部材に付記している。ただ、特許請求の範囲に示される部材を、実施例の部材に特定するものでは決してない。
【００１１】
図１ないし図６に示すパック電池は、ふたつの薄型電池１を積層して、これに回路基板７を連結している電池コア１５をケース１２に収納している。電池コア１５を、図６ないし図１２に示している。電池コア１５は、凸部電極端面３に凸部電極２を設けており、この凸部電極端面３と反対側の電極端面である底側端面４を凸部電極２と異なる極性の電極とする薄型電池１を積層している。薄型電池１は、正負の電極と電解液を外装缶に入れ、この外装缶の開口部を、凸部電極２のある封口板で閉塞して製作される。外装缶は、金属板をプレス加工して製作される。封口板はレーザー溶接して、あるいはカシメられて外装缶に気密に固定される。この薄型電池１は、凸部電極２と外装缶とを正負の異なる電極としている。凸部電極を負極とする薄型電池は、外装缶を正極とし、凸部電極を正極とする薄型電池は、外装缶を負極とする。薄型電池１はリチウムイオン電池である。ただし、薄型電池は、ニッケル−水素電池やニッケル−カドミウム電池、ポリマー電池等のように、充電できるすべての二次電池とすることができる。
【００１２】
ふたつの薄型電池１は、図７の斜視図と図８の断面図に示すように、一方の薄型電池１の凸部電極端面３と他方の薄型電池１の底側端面４とが同一平面に位置する姿勢で積層される。積層されたふたつの薄型電池１は、図８の断面図に示すように、凸部電極２と底側端面４とに中間リード８を連結するので、凸部電極２の先端面と底側端面４とをほぼ同一面とするようにして積層される。ただ、凸部電極端面の平面部と底側端面とを同一平面とするように積層して、中間リードを連結することもできる。金属板である中間リードを曲げて凸部電極と底側端面とに連結できるからである。
【００１３】
電池コア１５は、ひとつの薄型電池１の凸部電極端面３と、他方の薄型電池１の底側端面４とが位置する第１の端面５（図８において薄型電池１の左側の端面）に対向して回路基板７を配置している。回路基板７は、第１の端面５の外形にほぼ等しい外形としている。この回路基板７は、第１の端面５に対向して、第１の端面５と平行な姿勢で配設されて、薄型電池１から外部に突出しない。回路基板は、第１の端面の外形よりも小さくすることもできる。小さい回路基板も薄型電池の外側に突出しないからである。ただし、回路基板を第１の端面よりもわずかに大きくすることもできる。
【００１４】
回路基板７は、電池の保護回路を実現する電子部品２５と、出力端子１６とを固定している。図の電池コア１５は、出力端子１６を端子ホルダー１７に固定して、回路基板７に連結している。回路基板７に実装される保護回路は、図１３の回路図に示すように、パック電池の出力端子１６と薄型電池１との間に接続される。この回路図のパック電池は、保護回路１８と保護素子１０の両方を備えており、保護素子１０を各々の薄型電池１と直列に接続している。パック電池は、保護素子１０を介して薄型電池１を回路基板７に接続している。保護素子１０は電池に過電流が流れ、あるいは電池温度が設定温度よりも高くなると電流を遮断する素子である。図の回路図のパック電池は、保護素子１０をＰＴＣとしている。ただし、保護素子には、ＰＴＣに代わって、ブレーカやヒューズ等も使用できる。このパック電池は、保護素子１０と保護回路１８の両方で二重に電池を保護する。パック電池は、必ずしも保護回路と保護素子の両方を備える必要はない。保護回路と保護素子のいずれかひとつの保護回路を設けることもできる。さらに、薄型電池をニッケル−水素電池やニッケル−カドミウム電池とするパック電池は、保護回路と保護素子の両方を省略することもできる。
【００１５】
回路基板７は、中間リード８と一対の端部リード９を介して薄型電池１に連結される。中間リード８は、回路基板７の中間、好ましくはほぼ中央部分に連結される。一対の端部リード９は、回路基板７の両端部分に連結される。中間リード８と端部リード９は金属板で製作される。中間リード８と端部リード９の金属板は、ニッケル板、あるいは表面をニッケルメッキした金属板である。金属板である中間リード８と端部リード９は、スポット溶接して確実に薄型電池１の電極と回路基板７に連結される。中間リード８と端部リード９をスポット溶接して連結する回路基板７は、スポット溶接する部分に、金属プレートを半田付け等の方法で固定している。中間リード８と端部リード９は半田付けして回路基板７に連結することもできる。この回路基板７は、金属プレートを固定することなく、回路基板７の表面に設けている導電部に、中間リード８と端部リード９を直接に半田付けして固定できる。中間リード８と端部リード９は、薄型電池１の電極にはスポット溶接のみでなく、レーザー溶接あるいは超音波溶接して連結することもできる。
【００１６】
中間リード８は、図７と図８に示すように、回路基板７と対向する第１の端面５に位置する凸部電極２と底側端面４とに接続されて、ふたつの薄型電池１を互いに直列に電気接続する。中間リード８は、第１の端面５の中央部分を横方向に横断して、凸部電極２と底側端面４とに連結され、さらに、第１の端面５と対向して配置している回路基板７の中間部分に接続される。回路基板７は第１の端面５と平行に配設されるので、中間リード８は、図８の断面図に示すように、回路基板７の片方の側縁でＵ曲されて、その先端部分を回路基板７に連結している。中間リード８は、第１の端面５においてふたつの薄型電池１に連結され、さらに第１の端面５に対向して配設している回路基板７の中間部分に連結するので、最短距離で薄型電池１を回路基板７に連結する。この中間リード８は、ふたつの薄型電池１を互いに直列に電気接続すると共に、回路基板７を薄型電池１に連結する部材にも併用される。さらに、中間リード８は、各々の薄型電池１の電圧を測定する電圧検出用のリードとしても使用される。回路基板７に連結された中間リード８は保護回路に接続されており、中間リード８を介して各々の薄型電池１の電圧が検出される。このように、各々の薄型電池１の電圧を独立して検出できるパック電池は、各々の薄型電池１を理想的に制御できる。
【００１７】
一対の端部リード９は、回路基板７の両端部分に接続される。一対の端部リード９と中間リード８は、回路基板７の片方の側縁で折曲されている。この電池コア１５は、図７に示すように、回路基板７を第１の端面５と直角な姿勢として、中間リード８と端部リード９を回路基板７と薄型電池１に連結した後、中間リード８と端部リード９を折曲して、回路基板７を第１の端面５と平行な姿勢とする。この電池コア１５は、中間リード８と端部リード９の一端を回路基板７に接続した後、中間リード８と端部リード９を薄型電池１に連結できる。また、中間リード８と端部リード９を薄型電池１に連結した後、回路基板７に連結することもできる。
【００１８】
図の電池コア１５は、一対の端部リード９の端部を、第１の端面５の反対側にある第２の端面６に位置している薄型電池１の凸部電極２と底側端面４とに接続している。端部リード９は、保護素子１０を介して薄型電池１の電極に接続している。図の電池コア１５は、一方の端部リード９に接続している保護素子１０をひとつの薄型電池１の凸部電極端面３の平面部に配置して、他方の端部リード９に接続している保護素子１０を薄型電池１の側面に配置している。このように、凸部電極端面３の平面部に保護素子１０を配置する構造は、図９に示すように、凸部電極２の側部のスペースを有効に利用して保護素子１０を省スペースに配設できるので、パック電池の外形を小さくできる特長がある。この構造のパック電池は、保護素子１０に、電池温度を検出して電流を遮断する素子を使用する。このパック電池は、各々の保護素子１０で、各々の薄型電池１の温度を検出して電流を遮断するので、いずれの薄型電池１の温度が異常に高くなっても、保護素子１０で電池の電流を遮断できる。ただし、本発明のパック電池は、両方の保護素子を薄型電池の底側端面に配置し、あるいは薄型電池の側面に配置することもできる。
【００１９】
第２の端面６に一対の端部リード９を連結しているパック電池は、図８と図１４の断面図に示すように、第２の端面６で端部リード９が互いに接近する。そして、互いに接近する一対の端部リード９を確実に絶縁するために、図のパック電池は、積層している薄型電池１の間に絶縁材１１を配設している。絶縁材１１は、第２の端面６から突出して、第２の端面６の凸部電極２と底側端面４とに接続している一対の端部リード９の間に配置している。さらに、図１４のパック電池は、ケース１２の内面であって絶縁材１１と対向する位置に凹部１３を設けて、凹部１３の両側に、薄型電池１の凸部電極端面３と底側端面４に向かって突出する突出部１４を設けて、ケース１２の突出部１４と電極端面との間に端部リード９を配設している。この構造のパック電池は、仮に端部リード９が薄型電池１の底側端面４から外れても、他の端部リード９や底側端面４に接触してショートすることがない。外れた端部リード９が絶縁材１１を越えて隣に移動するのを阻止できるからである。図５と図１４のケース１２は、内面の突出部１４と対向する外側に、パック電池を装着している機器から取り出すための取出凹部１９と、パック電池を機器に装着するために機器に設けている嵌合用爪（図示せず）を案内する嵌合用凹部２０とを設けている。このケース１２は、外側に設けている取出凹部１９と嵌合用凹部２０を利用して、内側に突出部１４を設けることができる。
【００２０】
以上のパック電池は、以下のようにして製造される。
（１）第１の端面５に凸部電極２を配置している薄型電池１の凸部電極端面３に絶縁材２１を接着する。絶縁材２１は、凸部電極２を外部に表出させる貫通孔を設けている。したがって、凸部電極端面３に絶縁材２１を接着する状態で、凸部電極２は外部に表出している。
（２）薄型電池１の電極にクラッド材をスポット溶接して固定する。クラッド材は、中間リード８と端部リード９をスポット溶接するための金属板であるから、中間リード８と端部リード９をスポット溶接して連結する部分に固定される。中間リードと端部リードを電極に直接にスポット溶接できる薄型電池は、クラッド材を固定する必要はない。
（３）ふたつの薄型電池１を、絶縁材１１を介在して接着して積層する。絶縁材１１は、第２の端面６から突出するように薄型電池１の間に配設される。薄型電池１は、絶縁材１１の表面に設けている粘着層を介して接着される。さらに、絶縁材１１の表面に両面接着テープを付着して薄型電池１を接着することもできる。互いに接着して連結している薄型電池１は、その後の工程を簡単にできる。
（３）図７に示すように、積層している薄型電池１の両側に絶縁材２２を接着する。この絶縁材２２は、図に示すように、第１の端面５の両端部分を被覆する長さを有し、第１の端面５の両端部分を被覆する。
（４）図１５に示すように、回路基板７に中間リード８と一対の端部リード９をスポット溶接して連結する。中間リード８と端部リード９は、半田付けして回路基板７に連結することもできる。中間リード８と端部リード９は、回路基板７の片側で折曲されるので、片側から外側に突出する姿勢で、回路基板７に連結される。図の回路基板７は下方に突出するように、中間リード８と端部リード９を連結している。端部リード９は、あらかじめ端部に保護素子１０を連結している。各部にストレスがかからないように注意して、中間リード８と端部リード９を、回路基板７の片側で直角に折曲する。
（５）中間リード８の端部を第１の端面５の凸部電極２と底側端面４とにスポット溶接してふたつの薄型電池１を直列に連結する。さらに、一対の端部リード９を、第１の端面５の両端で薄型電池１の隅部に沿うように折曲し、さらに第２の端面６の両側で薄型電池１の隅部に沿うように折曲して、各々の端部を第２の端面６の凸部電極２と底側端面４に連結する。
（６）第１の端面５と回路基板７との間に絶縁材２３を配設し、この絶縁材２３を挟むように、中間リード８と端部リード９を折曲して、回路基板７を第１の端面５と平行な姿勢とする。
（７）図１０と図１１のハッチングで示すように、電池コア１５の側面に、端部リード９の一部あるいは全部を被覆するように絶縁材２４を接着する。
（８）以上にようにして製作された電池コア１５を、ケース１２に収納してケース１２を閉塞する。ケース１２は第１ケース１２Ａと第２ケース１２Ｂからなり、第１ケース１２Ａと第２ケース１２Ｂの周壁を超音波溶着し、あるいは接着し、あるいは嵌着して連結する。
【００２１】
【発明の効果】
本発明のパック電池は、回路基板と薄型電池とを理想的な配置で連結して、回路基板をしっかりと薄型電池に連結できる特長がある。それは、本発明のパック電池が、一方の薄型電池の凸部電極端面と他方の薄型電池の底側端面とを同一平面に位置するようにふたつの薄型電池を積層して、凸部電極端面と底側端面とが位置している第１の端面に対向して回路基板を配置し、この回路基板の中間に接続している中間リードを、回路基板と対向する第１の端面の凸部電極と底側端面に接続してふたつの薄型電池を直列に電気接続して回路基板に連結し、さらに、回路基板の両端部分に一対の端部リードを接続して、中間リードと端部リードを回路基板の片方の側縁で折曲して、一対の端部リードをひとつの薄型電池の凸部電極と他方の薄型電池の凸部電極と反対側の電極に接続しているからである。この構造のパック電池は、短い中間リードでふたつの薄型電池を直列に電気接続して、しかも薄型電池を回路基板に最短距離で連結できる。このため、中間リードでもって、ふたつの薄型電池を極めて低抵抗な状態で直列に電気接続しながらしっかりと回路基板に連結できる。
【００２２】
また、本発明のパック電池は、中間リードで薄型電池に連結している回路基板の両端に一対の端部リードを接続しており、端部リードを薄型電池に連結しているので、薄型電池の正負の電極に接続している一対の端部リードの短絡を確実に阻止して回路基板に連結できる特長もある。
【図面の簡単な説明】
【図１】本発明の一実施例にかかるパック電池の正面図
【図２】図１に示すパック電池の右側面図
【図３】図１に示すパック電池の左側面図
【図４】図１に示すパック電池の平面図
【図５】図１に示すパック電池の底面図
【図６】図１に示すパック電池の分解斜視図
【図７】図６に示す電池コアを反転して回路基板を展開した状態を示す斜視図
【図８】電池コアの断面図であって図１２のＡ−Ａ線断面に相当する図
【図９】電池コアの正面図
【図１０】図９に示す電池コアの右側面図
【図１１】図９に示す電池コアの左側面図
【図１２】図９に示す電池コアの平面図
【図１３】本発明の一実施例にかかるパック電池の回路図
【図１４】図１に示すパック電池のＡ−Ａ線断面図及び一部拡大断面図
【図１５】中間リードと端部リードを回路基板に連結した状態を示す平面図
【符号の説明】
１…薄型電池
２…凸部電極
３…凸部電極端面
４…底側端面
５…第１の端面
６…第２の端面
７…回路基板
８…中間リード
９…端部リード
１０…保護素子
１１…絶縁材
１２…ケース１２Ａ…第１ケース１２Ｂ…第２ケース
１３…凹部
１４…突出部
１５…電池コア
１６…出力端子
１７…端子ホルダー
１８…保護回路
１９…取出凹部
２０…嵌合用凹部
２１…絶縁材
２２…絶縁材
２３…絶縁材
２４…絶縁材
２５…電子部品[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a battery pack containing two thin batteries.
[0002]
[Prior art]
A battery pack in which a thin battery is built in a case is described in, for example, Japanese Patent Application Laid-Open Publication No. H10-157,036. In this battery pack, a circuit board is arranged on an electrode end surface of the thin battery, and the circuit board and the thin battery are connected by a pair of leads. In the battery pack of this structure, one thin battery is housed in the case, so that the thin battery can be connected to the circuit board with two leads. In this manner, with the structure in which the circuit board is arranged on the electrode end face, two thin batteries can be stacked and housed in the case. The two batteries are connected in parallel or in series. In a battery pack in which batteries are connected in parallel and stored in a case, the thin batteries are stacked in such a manner that the thin batteries are oriented in the same direction, that is, the convex electrode end faces of the thin batteries are flush with each other. The external electrodes and the electrodes on the bottom end face can be connected by leads. In a battery pack in which batteries are connected in series, when two thin batteries are stacked in the same direction, the leads connected in series become longer. This disadvantage can be solved by stacking two thin batteries in opposite directions. In the reverse thin battery, the end face of the protruding electrode of one thin battery and the bottom end face of the other thin battery are located on the same plane, so that they can be connected in series with short leads. Furthermore, a circuit board is arranged on the end face of the electrode opposite to the lead connecting the batteries in series, and the protruding electrode of the battery and the electrode on the bottom end face are connected by a lead, and the circuit board and the battery are connected by a short lead. Can connect. Therefore, in the battery pack of this structure that is connected in series, the batteries can be connected in series with the shortest lead, and a thin battery can be connected to the circuit board.
[0003]
[Patent Document 1]
Japanese Patent Application Laid-Open No. 2002-8608
[Problems to be solved by the invention]
However, with the above structure, it is difficult to securely connect the circuit board to the thin batteries, and in order to independently detect the voltage of each thin battery, the opposite side where the thin batteries are connected in series is required. Lead must be connected to the circuit board, and there is a disadvantage that the lead for voltage detection becomes long. The present invention has been developed with the aim of further solving this drawback.The present invention can connect a circuit board and a thin battery in an ideal arrangement, and can securely connect the circuit board to the thin battery. Another object of the present invention is to provide a battery pack that can be connected to a circuit board while reliably preventing a short circuit between a pair of end leads connected to positive and negative electrodes of a thin battery connected in series.
[0005]
[Means for Solving the Problems]
In the battery pack of the present invention, two thin batteries 1 are stacked. In the thin battery 1, the convex electrode 2 is provided on the convex electrode end surface 3, and the bottom end surface 4, which is the electrode end surface opposite to the convex electrode end surface 3, is an electrode having a polarity different from that of the convex electrode 2. The two thin batteries 1 are stacked such that the convex electrode end face 3 of one thin battery 1 and the bottom end face 4 of the other thin battery 1 are located on the same end face. Further, in the battery pack, the circuit board 7 is disposed so as to face the first end face 5 where the convex electrode end face 3 of one thin battery 1 and the bottom end face 4 of the other thin battery 1 are located. An intermediate lead 8 is connected to the convex electrode end face 3 and the bottom end face 4 located on the first end face 5 facing the circuit board 7, and the two thin batteries 1 are electrically connected to each other in series with the intermediate lead 8, Further, the intermediate lead 8 is connected to an intermediate portion of the circuit board 7. A pair of end leads 9 are connected to both end portions of the circuit board 7, and the intermediate lead 8 and the end lead 9 are bent at one side edge of the circuit board 7. One end of the pair of end leads 9 is connected to the protruding electrode 2 of one thin battery 1, and the other is connected to the electrode on the opposite side of the protruding electrode 2 of the other thin battery 1. The circuit board 7 is connected to the two thin batteries 1 with the unit leads 9.
[0006]
In the battery pack, the pair of end leads 9 can be connected to the electrodes of the thin battery 1 via the protection element 10.
[0007]
Further, in the battery pack, the ends of the pair of end leads 9 are connected to the convex electrode 2 and the bottom end surface 4 of the thin battery 1 located on the second end surface 6 opposite to the first end surface 5. And can be connected to. Further, in the battery pack, an insulating material 11 is provided between the thin batteries 1, and the insulating material 11 is made to protrude from the second end face 6 so as to be in contact with the convex electrode end face 3 of the second end face 6 and the bottom side. It is arranged between a pair of end leads 9 connected to the end face 4 and the end leads 9 can be reliably insulated by the insulating material 11.
[0008]
In the battery pack, the thin battery 1 is housed in a case 12, and a recess 13 is provided on the inner surface of the case 12 at a position facing the insulating material 11, so that the insulating material 11 insulates the pair of end leads 9 more reliably. it can. Further, on both sides of the concave portion 13 provided on the inner surface of the case 12, a protruding portion 14 protruding toward the protruding electrode end surface 3 and the bottom end surface 4 of the thin battery 1 is provided. By disposing the end leads 9 between them, the pair of end leads 9 can be more reliably insulated.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the following examples illustrate a battery pack for embodying the technical idea of the present invention, and the present invention does not specify a battery pack as follows.
[0010]
Further, in this specification, in order to make it easy to understand the claims, the numbers corresponding to the members shown in the embodiments are referred to as “claims” and “means for solving the problems”. Are added to the members indicated by "." However, the members described in the claims are not limited to the members of the embodiments.
[0011]
In the battery pack shown in FIGS. 1 to 6, two thin batteries 1 are stacked, and a battery core 15 connecting the circuit board 7 to the thin batteries 1 is housed in a case 12. The battery core 15 is shown in FIGS. In the battery core 15, the convex electrode 2 is provided on the convex electrode end surface 3, and the bottom end surface 4, which is an electrode end surface opposite to the convex electrode end surface 3, is an electrode having a polarity different from that of the convex electrode 2. Thin batteries 1 are stacked. The thin battery 1 is manufactured by putting positive and negative electrodes and an electrolytic solution in an outer can, and closing an opening of the outer can with a sealing plate having a convex electrode 2. The outer can is manufactured by pressing a metal plate. The sealing plate is hermetically fixed to the outer can by laser welding or caulking. In this thin battery 1, the convex electrode 2 and the outer can are electrodes having different positive and negative electrodes. A thin battery having a convex electrode as a negative electrode has an outer can as a positive electrode, and a thin battery having a convex electrode as a positive electrode has an outer can as a negative electrode. The thin battery 1 is a lithium ion battery. However, the thin battery can be any rechargeable battery such as a nickel-hydrogen battery, a nickel-cadmium battery, a polymer battery, or the like.
[0012]
As shown in the perspective view of FIG. 7 and the cross-sectional view of FIG. 8, the two thin batteries 1 have the convex electrode end face 3 of one thin battery 1 and the bottom end face 4 of the other thin battery 1 on the same plane. They are stacked in the position where they are located. As shown in the cross-sectional view of FIG. 8, in the two thin batteries 1 that are stacked, the intermediate lead 8 is connected to the convex electrode 2 and the bottom end surface 4, so that the front end surface and the bottom end surface of the convex electrode 2 are connected. 4 are laminated so that they are substantially flush with each other. However, the intermediate lead can be connected by laminating the flat electrode end face and the bottom end face so as to be on the same plane. This is because the intermediate lead, which is a metal plate, can be bent and connected to the projection electrode and the bottom end surface.
[0013]
The battery core 15 is provided on the first end face 5 (the left end face of the thin battery 1 in FIG. 8) where the convex electrode end face 3 of one thin battery 1 and the bottom end face 4 of the other thin battery 1 are located. The circuit board 7 is arranged so as to face. The circuit board 7 has an outer shape substantially equal to the outer shape of the first end face 5. The circuit board 7 is disposed facing the first end face 5 in a posture parallel to the first end face 5 and does not protrude from the thin battery 1 to the outside. The circuit board may be smaller than the outer shape of the first end face. This is because even a small circuit board does not protrude outside the thin battery. However, the circuit board can be slightly larger than the first end face.
[0014]
The circuit board 7 fixes an electronic component 25 for realizing a battery protection circuit and the output terminal 16. In the illustrated battery core 15, the output terminal 16 is fixed to the terminal holder 17 and connected to the circuit board 7. The protection circuit mounted on the circuit board 7 is connected between the output terminal 16 of the battery pack and the thin battery 1 as shown in the circuit diagram of FIG. The battery pack of this circuit diagram includes both the protection circuit 18 and the protection element 10, and the protection element 10 is connected in series with each thin battery 1. In the battery pack, the thin battery 1 is connected to a circuit board 7 via a protection element 10. The protection element 10 is an element that cuts off the current when an overcurrent flows through the battery or when the battery temperature becomes higher than a set temperature. In the battery pack shown in the circuit diagram, the protection element 10 is a PTC. However, a breaker, a fuse or the like can be used for the protection element instead of the PTC. In this battery pack, both the protection element 10 and the protection circuit 18 protect the battery doubly. The battery pack does not necessarily need to include both the protection circuit and the protection element. Any one of the protection circuit and the protection element may be provided. Further, in a battery pack in which a thin battery is a nickel-hydrogen battery or a nickel-cadmium battery, both the protection circuit and the protection element can be omitted.
[0015]
The circuit board 7 is connected to the thin battery 1 via an intermediate lead 8 and a pair of end leads 9. The intermediate lead 8 is connected to an intermediate part, preferably a substantially central part, of the circuit board 7. The pair of end leads 9 are connected to both end portions of the circuit board 7. The intermediate lead 8 and the end lead 9 are made of a metal plate. The metal plate of the intermediate lead 8 and the end lead 9 is a nickel plate or a metal plate whose surface is nickel-plated. The intermediate lead 8 and the end lead 9 that are metal plates are spot-welded and securely connected to the electrodes of the thin battery 1 and the circuit board 7. The circuit board 7, which connects the intermediate lead 8 and the end lead 9 by spot welding, has a metal plate fixed to the spot to be welded by a method such as soldering. The intermediate lead 8 and the end lead 9 can be connected to the circuit board 7 by soldering. The circuit board 7 can be fixed by directly soldering the intermediate lead 8 and the end lead 9 to the conductive portion provided on the surface of the circuit board 7 without fixing the metal plate. The intermediate lead 8 and the end lead 9 can be connected to the electrode of the thin battery 1 not only by spot welding but also by laser welding or ultrasonic welding.
[0016]
As shown in FIGS. 7 and 8, the intermediate lead 8 is connected to the convex electrode 2 located on the first end face 5 facing the circuit board 7 and the bottom end face 4 so that the two thin batteries 1 can be connected. Electrically connected to each other in series. The intermediate lead 8 traverses a central portion of the first end face 5 in the lateral direction, is connected to the protruding electrode 2 and the bottom end face 4, and is arranged to face the first end face 5. It is connected to the middle part of the circuit board 7. Since the circuit board 7 is disposed in parallel with the first end surface 5, the intermediate lead 8 is bent at one side edge of the circuit board 7 as shown in the sectional view of FIG. Are connected to the circuit board 7. The intermediate lead 8 is connected to the two thin batteries 1 at the first end face 5 and is further connected to an intermediate portion of the circuit board 7 disposed opposite to the first end face 5, so that the intermediate lead 8 is thin at the shortest distance. The battery 1 is connected to the circuit board 7. The intermediate lead 8 electrically connects the two thin batteries 1 to each other in series and is also used as a member for connecting the circuit board 7 to the thin batteries 1. Furthermore, the intermediate lead 8 is also used as a voltage detecting lead for measuring the voltage of each thin battery 1. The intermediate lead 8 connected to the circuit board 7 is connected to a protection circuit, and the voltage of each thin battery 1 is detected via the intermediate lead 8. In this way, a battery pack that can independently detect the voltage of each thin battery 1 can ideally control each thin battery 1.
[0017]
The pair of end leads 9 are connected to both end portions of the circuit board 7. The pair of end leads 9 and the intermediate lead 8 are bent at one side edge of the circuit board 7. As shown in FIG. 7, the battery core 15 has the circuit board 7 in a posture perpendicular to the first end face 5, and connects the intermediate lead 8 and the end lead 9 to the circuit board 7 and the thin battery 1. The circuit board 7 is oriented parallel to the first end face 5 by bending the leads 8 and the end leads 9. This battery core 15 can connect the intermediate lead 8 and the end lead 9 to the thin battery 1 after connecting one end of the intermediate lead 8 and the end lead 9 to the circuit board 7. Further, after connecting the intermediate lead 8 and the end lead 9 to the thin battery 1, it can be connected to the circuit board 7.
[0018]
In the battery core 15 shown in the figure, the ends of the pair of end leads 9 are connected to the convex electrode 2 of the thin battery 1 located on the second end face 6 on the opposite side of the first end face 5 and the bottom end face. 4 and connected. The end lead 9 is connected to an electrode of the thin battery 1 via a protection element 10. In the battery core 15 shown in the figure, the protection element 10 connected to one end lead 9 is arranged on the flat surface of the convex electrode end face 3 of one thin battery 1 and connected to the other end lead 9. The protective element 10 is disposed on the side surface of the thin battery 1. In this manner, the structure in which the protection element 10 is arranged on the flat surface of the end face 3 of the projection electrode, as shown in FIG. 9, effectively saves the space of the protection element 10 by using the space on the side of the projection electrode 2. The advantage is that the external shape of the battery pack can be reduced. The battery pack having this structure uses an element for detecting the battery temperature and interrupting the current as the protection element 10. In this battery pack, each protection element 10 detects the temperature of each thin battery 1 and cuts off the current. Therefore, even if the temperature of any thin battery 1 becomes abnormally high, the protection element 10 Can cut off current. However, in the battery pack of the present invention, both protection elements can be arranged on the bottom end face of the thin battery, or can be arranged on the side face of the thin battery.
[0019]
In the battery pack in which the pair of end leads 9 are connected to the second end face 6, the end leads 9 approach each other at the second end face 6, as shown in the sectional views of FIGS. In order to reliably insulate a pair of end leads 9 approaching each other, the battery pack shown in the figure has an insulating material 11 disposed between the stacked thin batteries 1. The insulating material 11 protrudes from the second end face 6 and is disposed between a pair of end leads 9 connected to the protruding electrode 2 of the second end face 6 and the bottom end face 4. Further, in the battery pack of FIG. 14, a concave portion 13 is provided on the inner surface of the case 12 so as to face the insulating material 11, and the convex electrode end surface 3 and the bottom end surface 4 of the thin battery 1 are provided on both sides of the concave portion 13. The end lead 9 is provided between the protrusion 14 of the case 12 and the electrode end face. In the battery pack having this structure, even if the end lead 9 is detached from the bottom end face 4 of the thin battery 1, it does not come into contact with the other end lead 9 or the bottom end face 4 to cause a short circuit. This is because the detached end lead 9 can be prevented from moving beyond the insulating material 11 to the adjacent position. The case 12 shown in FIGS. 5 and 14 is provided on the outside facing the protrusion 14 on the inner surface, for taking out the battery from the device in which the battery pack is mounted, and in the device for mounting the battery pack in the device. And a fitting recess 20 for guiding the fitting claw (not shown). In this case 12, the protrusion 14 can be provided inside by using the extraction recess 19 and the fitting recess 20 provided on the outside.
[0020]
The above battery pack is manufactured as follows.
(1) The insulating material 21 is bonded to the convex electrode end surface 3 of the thin battery 1 in which the convex electrode 2 is disposed on the first end surface 5. The insulating material 21 has a through hole for exposing the projection electrode 2 to the outside. Therefore, in a state where the insulating material 21 is adhered to the end surface 3 of the projection electrode, the projection electrode 2 is exposed to the outside.
(2) The clad material is fixed to the electrode of the thin battery 1 by spot welding. Since the clad material is a metal plate for spot welding the intermediate lead 8 and the end lead 9, it is fixed to a portion where the intermediate lead 8 and the end lead 9 are connected by spot welding. A thin battery in which the intermediate lead and the end lead can be spot-welded directly to the electrode does not need to fix the clad material.
(3) The two thin batteries 1 are laminated by bonding with the insulating material 11 interposed therebetween. The insulating material 11 is provided between the thin batteries 1 so as to protrude from the second end face 6. The thin battery 1 is bonded via an adhesive layer provided on the surface of the insulating material 11. Further, the thin battery 1 can be bonded by attaching a double-sided adhesive tape to the surface of the insulating material 11. The thin batteries 1 bonded and connected to each other can simplify the subsequent steps.
(3) As shown in FIG. 7, the insulating materials 22 are bonded to both sides of the thin battery 1 stacked. As shown in the figure, the insulating material 22 has a length covering both end portions of the first end face 5, and covers both end portions of the first end face 5.
(4) As shown in FIG. 15, the intermediate lead 8 and the pair of end leads 9 are connected to the circuit board 7 by spot welding. The intermediate lead 8 and the end lead 9 can be connected to the circuit board 7 by soldering. Since the intermediate lead 8 and the end lead 9 are bent on one side of the circuit board 7, they are connected to the circuit board 7 in a posture protruding outward from one side. The illustrated circuit board 7 connects the intermediate lead 8 and the end lead 9 so as to protrude downward. The end lead 9 has a protection element 10 connected to the end in advance. The intermediate lead 8 and the end lead 9 are bent at a right angle on one side of the circuit board 7 so that stress is not applied to each part.
(5) The two thin batteries 1 are connected in series by spot welding the end of the intermediate lead 8 to the projection electrode 2 of the first end face 5 and the bottom end face 4. Further, a pair of end leads 9 are bent at both ends of the first end face 5 along the corners of the thin battery 1, and further along both sides of the second end face 6 along the corners of the thin battery 1. And each end is connected to the convex electrode 2 of the second end face 6 and the bottom end face 4.
(6) An insulating material 23 is provided between the first end face 5 and the circuit board 7, and the intermediate lead 8 and the end lead 9 are bent so as to sandwich the insulating material 23, and Is in a posture parallel to the first end face 5.
(7) As shown by hatching in FIGS. 10 and 11, an insulating material 24 is adhered to the side surface of the battery core 15 so as to cover part or all of the end leads 9.
(8) The battery core 15 manufactured as described above is stored in the case 12 and the case 12 is closed. The case 12 includes a first case 12A and a second case 12B, and the peripheral walls of the first case 12A and the second case 12B are connected by ultrasonic welding, bonding, or fitting.
[0021]
【The invention's effect】
The battery pack of the present invention has a feature that the circuit board and the thin battery can be connected in an ideal arrangement, and the circuit board can be firmly connected to the thin battery. That is, the battery pack of the present invention is formed by stacking two thin batteries so that the convex electrode end face of one thin battery and the bottom end face of the other thin battery are located on the same plane, and the convex electrode end face. A circuit board is arranged so as to face the first end face where the bottom end face is located, and an intermediate lead connected in the middle of the circuit board is connected to a convex electrode on the first end face facing the circuit board. The two thin batteries are connected in series to the circuit board by connecting them to the bottom end face, and furthermore, a pair of end leads are connected to both ends of the circuit board, and the intermediate lead and the end lead are connected. This is because the circuit board is bent at one side edge, and a pair of end leads are connected to the protruding electrode of one thin battery and the electrode on the other side of the protruding electrode of the other thin battery. In the battery pack having this structure, two thin batteries can be electrically connected in series with a short intermediate lead, and the thin batteries can be connected to the circuit board in the shortest distance. For this reason, the two thin batteries can be firmly connected to the circuit board with the intermediate leads while electrically connecting the two thin batteries in series with extremely low resistance.
[0022]
In the battery pack of the present invention, a pair of end leads are connected to both ends of a circuit board connected to the thin battery with intermediate leads, and the end leads are connected to the thin battery. There is also a feature that a short circuit of a pair of end leads connected to the positive and negative electrodes can be surely prevented from being connected to the circuit board.
[Brief description of the drawings]
FIG. 1 is a front view of a battery pack according to one embodiment of the present invention. FIG. 2 is a right side view of the battery pack shown in FIG. 1. FIG. 3 is a left side view of the battery pack shown in FIG. 1; FIG. 5 is a bottom view of the battery pack shown in FIG. 1; FIG. 6 is an exploded perspective view of the battery pack shown in FIG. 1; FIG. 7 is an inverted circuit of the battery core shown in FIG. FIG. 8 is a cross-sectional view of the battery core, showing a state in which the substrate is expanded. FIG. 8 is a cross-sectional view corresponding to a cross section taken along line AA of FIG. 12. FIG. 9 is a front view of the battery core. 11 is a left side view of the battery core shown in FIG. 9; FIG. 12 is a plan view of the battery core shown in FIG. 9; FIG. 13 is a circuit diagram of a battery pack according to one embodiment of the present invention. FIG. 14 is a cross-sectional view of the battery pack shown in FIG. 1 taken along the line AA and a partially enlarged cross-sectional view. Plan view showing the connecting state [EXPLANATION OF SYMBOLS]
DESCRIPTION OF SYMBOLS 1 ... Thin battery 2 ... Convex electrode 3 ... Convex electrode end face 4 ... Bottom end face 5 ... First end face 6 ... Second end face 7 ... Circuit board 8 ... Intermediate lead 9 ... End lead 10 ... Protection element 11 ... insulating material 12 ... case 12A ... first case 12B ... second case 13 ... recess 14 ... protrusion 15 ... battery core 16 ... output terminal 17 ... terminal holder 18 ... protection circuit 19 ... removal recess 20 ... fitting recess 21 ... Insulating material 22 Insulating material 23 Insulating material 24 Insulating material 25 Electronic components

Claims

A convex electrode (2) is provided on the convex electrode end surface (3), and a bottom end surface (4), which is an electrode end surface opposite to the convex electrode end surface (3), has a polarity different from that of the convex electrode (2). In the two thin batteries (1) used as the electrodes, the convex electrode end face (3) of one thin battery (1) and the bottom end face (4) of the other thin battery (1) are located on the same end face. So that
The circuit board (7) faces the first end face (5) where the end face (3) of the convex electrode of one thin battery (1) and the bottom end face (4) of the other thin battery (1) are located. And an intermediate lead (8) is connected to the convex electrode end face (3) and the bottom end face (4) located on the first end face (5) facing the circuit board (7). An intermediate lead (8) electrically connects the two thin batteries (1) in series with each other,
The intermediate lead (8) is connected to an intermediate portion of the circuit board (7), and a pair of end leads (9) are connected to both end portions of the circuit board (7). The lead (9) is bent at one side edge of the circuit board (7),
One of the pair of end leads (9) is connected to the convex electrode (2) of one thin battery (1) and the other is connected to the electrode on the opposite side of the convex electrode (2) of the other thin battery (1). And
A battery pack in which a circuit board (7) is connected to two thin batteries (1) by an intermediate lead (8) and an end lead (9).

The battery pack according to claim 1, wherein the pair of end leads (9) are connected to the electrodes of the thin battery (1) via the protection element (10).

The ends of the pair of end leads (9) are connected to the convex electrode (2) of the thin battery (1) located on the second end face (6) opposite to the first end face (5). The battery pack according to claim 1, which is connected to the bottom end surface (4).

An insulating material (11) is provided between the thin batteries (1), and the insulating material (11) is projected from the second end face (6) to form a projection on the second end face (6). The battery pack according to claim 3, wherein the battery pack is disposed between a pair of end leads (9) connected to the electrode end face (3) and the bottom end face (4).

The thin battery (1) is housed in a case (12), and a concave portion (13) is provided on the inner surface of the case (12) at a position facing the insulating material (11). Battery pack.

On both sides of the concave portion (13) provided on the inner surface of the case (12), projecting portions (14) projecting toward the convex electrode end surface (3) and the bottom end surface (4) of the thin battery (1) are provided. The battery pack according to claim 5, wherein an end lead (9) is provided between the protrusion (14) and the electrode end face.